Journal of Nanoscience and Nanotechnology
Biosynthesis of Silver Nanoparticles Using the Fungus Pleurotusostreatus and their Antibacterial Activity.
PDF Downloads : Oriental Journal of Chemistry
Highly monodisperse sodium citrate-coated spherical silver nanoparticles (Ag NPs) with controlled sizes ranging from 10 to 200 nm have been synthesized by following a kinetically controlled seeded-growth approach via the reduction of silver nitrate by the combination of two chemical reducing agents: sodium citrate and tannic acid. The use of traces of tannic acid is fundamental in the synthesis of silver seeds, with an unprecedented (nanometric resolution) narrow size distribution that becomes even narrower, by size focusing, during the growth process. The homogeneous growth of Ag seeds is kinetically controlled by adjusting reaction parameters: concentrations of reducing agents, temperature, silver precursor to seed ratio, and pH. This method produces long-term stable aqueous colloidal dispersions of Ag NPs with narrow size distributions, relatively high concentrations (up to 6 × 1012 NPs/mL), and, more important, readily accessible surfaces. This was proved by studying the catalytic properties of as-synthesized Ag NPs using the reduction of Rhodamine B (RhB) by sodium borohydride as a model reaction system. As a result, we show the ability of citrate-stabilized Ag NPs to act as very efficient catalysts for the degradation of RhB while the coating with a polyvinylpyrrolidone (PVP) layer dramatically decreased the reaction rate.
A silver nanoparticle solution was prepared in one step by mixing AgNO3 and a multi-amino compound (RSD-NH2) solution under ambient condition. RSD-NH2 was in-house synthesized by methacrylate and polyethylene polyamine in methanol, which has abundant amino and imino groups. However, the characterization of silver nanoparticles indicated that these nanoparticles are easy to agglomerate in solution. Therefore, an in situ synthesis method of silver nanoparticles on the silk fabrics was developed. The examined results confirmed that the in situ synthesized silver nanoparticles were evenly distributed on the surface of fibers. The inhibition zone test and the antibacterial rate demonstrated that the finished fabrics have an excellent antibacterial property against Staphylococcus aureus and Escherichia coli. Moreover, the nanosilver-treated silk fabrics were laundered 0, 5, 10, 20, and 50 times and still retained the exceptional antibacterial property. When the treated fabrics were washed 50 times, the antibacterial rate is more than 97.43% for S. aureus and 99.86% for E. coli. The excellent laundering durability may be attributed to the tight binding between silver nanoparticles and silk fibers through the in situ synthesis. This method provides an economic method to enhance the antibacterial capability of silk fabrics with good resistance to washings.
Nanoscience and Nanotechnology Letters
. Chung IM, Inmyoung Park, Kim Seung-Hyun, Muthu Thiruvengadam, Govindasamy Raja kumar. Plant-Mediated Synthesis of Silver Nanoparticles: Their Characteristic Properties and Therapeutic Applications. Nanoscale Research Letter. 2016; 11(40): 1-14.
A silver nanoparticle solution was prepared in one step by mixing AgNO3 and RSD-NH2 solution under vigorous stirring at room temperature. The multi-amino compound (RSD-NH2), which has abundant amino and imino groups, was synthesized by methacrylate and polyethylene polyamine in methanol. The formation of silver nanoparticles was characterized by various methods. However, the results indicated that silver nanoparticles easily agglomerate in ambient condition. Therefore, an in situ synthesis method was conducted through the reaction between the multi-amino compound (RSD-NH2) and the silver nitrate solution. The surface morphology, whiteness, silver content, antibacterial activity, and washing durability of nanosilver-treated fabrics were examined. The experimental results confirmed that the in situ synthesized silver nanoparticles evenly distributed on the surface of fibers. The inhibition zone and the antibacterial rate demonstrated that the finished fabrics have an excellent antibacterial property against S. aureus and E. coli. When the nanosilver-treated fabric which included a silver content of 98.65 mg/kg was washed 50 times, the silver content slightly decreased from 98.65 to 81.65 mg/kg and the corresponding whiteness increased. However, it is surprising that the antibacterial rate is still more than 97.43% for S. aureus and 99.86% for E. coli after 50 washings.
Clinical Studies and Reports on Colloidal Silver
Purposes of this research are synthesis of stable silver nanoparticles by using chemical reduction without using toxic solvents and evaluation of antibacterial effects of silver nanoparticles on S. aureus and E. coli as two harmful and problematic bacteria in food.
The diverse applications of silver nanoparticles is due to their characteristic properties of magnetic and optical polarization, catalysis, electrical conductivity, antimicrobial properties, DNA sequencing and surface-enhanced Raman scattering Silver Nanoparticles, Nanomedicine, Synthesis, UV-Vis spectroscopy, Antifungal EfficacyNanomedicine is an emerging field of science which uses the applications of nanotechnology in the prevention and treatment of diseases in human body .
and showed strong antibacterial ..
Nanomedicine: Nanotechnology, Biology and Medicine
Ray assisted synthesis of silver nanoparticles in chitosan solution and the antibacterial properties
and present applications silver nanoparticles in medicine
30/06/2011 · Green Synthesis and Antibacterial Effect of Silver Nanoparticles Using Vitex Negundo L.
Synthesis, Properties, and Applications of Iron Nanoparticles
Today the synthesis of silver nanoparticles is very common due to their numerous applications in various fields
by Electrochemical Reduction Method and Their Antibacterial ..
Synthesis of noble metallic nanoparticles, in general, and silver nanoparticles (SNPs), in particular, currently are of special interest. In the present paper, an overview of the enhanced properties of SNPs and consequential applications of SNPs are discussed. Common synthesis methods and their comparison with the microemulsion technology, particularly advantages of SNPs formation with microemulsion technology, are discussed. A brief overview of the basics of microemulsion technology for nanoparticles formation is also presented. The complete topical review of microemulsion synthesis technique used to date for the generation of SNPs is discussed comprehensively. Control parameters have been explicated for influencing size, size uniformity, and stability aspects of the SNPs reported in the literature, allowing a tailored synthesis for specific application. Recent modifications made on the synthesis of SNPs to obtain monodisperse, high yield and stability are also discussed. Lastly, some future trends and perspectives in these research areas are outlined.
Ray assisted synthesis of silver nanoparticles in …
Antibacterial activity of the synthesized silver nanoparticles was tested with one Gram-positive (Staphylococcus aureus) and one Gram- negative (Escherichia coli) bacterium.
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